Abstract: A wavelength tunable laser includes: a heating layer, a dielectric layer, reflectors, a transport layer, a support layer, and a substrate layer. The heating layer is located above the transport layer; the transport layer is located above the support layer, and the transport layer includes an upper cladding layer, a waveguide layer, and a lower cladding layer from top to bottom; the reflector is located in the transport layer; the support layer has a protection structure, where the protection structure forms a hollow structure together with the transport layer and the substrate layer, and the hollow structure has a support structure; and the substrate layer is located below the support layer. The heating layer, the reflector, and a part of the transport layer form a suspended structure to prevent heat dissipation. Thus thermal tuning efficiency can be improved, and power consumption can be lowered.

Abstract: A tunable laser is provided, including a first reflector, a second reflector, a phase adjustment area, a gain area, a first detector, a second detector, and a controller. The phase adjustment area is located between the first reflector and the gain area, the gain area is located between the phase adjustment area and the second reflector, a reflectivity of the first reflector is adjustable, and a reflectivity of the second reflector is adjustable. The first detector is configured to convert an optical signal of the first reflector into a first electrical signal. The second detector is configured to convert an optical signal of the second reflector into a second electrical signal. The controller is configured to adjust at least one of the reflectivity of the first reflector or the reflectivity of the second reflector based on the first electrical signal and the second electrical signal.

Abstract: An optical transceiver comprising an optical signal input, a first modulation section coupled to the optical signal input, a second modulation section coupled to the optical signal input and positioned in serial with the first modulation section, wherein the first modulation section comprises a first digital electrical signal input, a first digital driver coupled to the first digital electrical signal input, and a first modulator coupled to the first digital driver, and wherein the second modulation section comprises a second digital electrical signal input, a second digital driver coupled to the second digital electrical signal input, and a second modulator coupled to the second digital driver, and an optical signal output coupled to the first modulation section and the second modulation section.

Abstract: An apparatus comprising a laser comprising an active layer and configured to emit an optical signal, wherein a temperature change of the laser causes the optical signal to shift in wavelength, and a heater thermally coupled to the active layer and configured to reduce a wavelength shift of the optical signal by applying heat to the active layer.

Abstract: An optical modulator comprises a silicon substrate, a buried oxide (BOX) layer disposed on top of the silicon substrate, and a ridge waveguide disposed on top of the BOX layer and comprising a first n-type silicon (n-Si) slab, a first gate oxide layer coupled to the first n-Si slab, a first p-type silicon (p-Si) slab coupled to the first gate oxide layer, and a light propagation path that travels sequentially through the first n-Si slab, the first gate oxide layer, and the first p-Si slab.

Abstract: A wavelength tunable laser includes: a heating layer, a dielectric layer, reflectors, a transport layer, a support layer, and a substrate layer. The heating layer is located above the transport layer; the transport layer is located above the support layer, and the transport layer includes an upper cladding layer, a waveguide layer, and a lower cladding layer from top to bottom; the reflector is located in the transport layer; the support layer has a protection structure, where the protection structure forms a hollow structure together with the transport layer and the substrate layer, and the hollow structure has a support structure; and the substrate layer is located below the support layer. The heating layer, the reflector, and a part of the transport layer form a suspended structure to prevent heat dissipation. Thus thermal tuning efficiency can be improved, and power consumption can be lowered.

Abstract: A metal-oxide semiconductor (MOS) optical modulator including a doped semiconductor layer having a waveguide structure, a dielectric layer disposed over the waveguide structure of the doped semiconductor layer, a gate region disposed over the dielectric layer, wherein the gate region comprises a transparent electrically conductive material having a refractive index lower than that of silicon, and a metal contact disposed over the gate region. The metal contact, the gate region, and the waveguide structure of the doped semiconductor layer may be vertically aligned with each other.

Abstract: A tunable laser is provided, including a first reflector, a second reflector, a phase adjustment area, a gain area, a first detector, a second detector, and a controller. The phase adjustment area is located between the first reflector and the gain area, the gain area is located between the phase adjustment area and the second reflector, a reflectivity of the first reflector is adjustable, and a reflectivity of the second reflector is adjustable. The first detector is configured to convert an optical signal of the first reflector into a first electrical signal. The second detector is configured to convert an optical signal of the second reflector into a second electrical signal. The controller is configured to adjust at least one of the reflectivity of the first reflector or the reflectivity of the second reflector based on the first electrical signal and the second electrical signal.

Abstract: An apparatus comprises: a first input tap; a first optical modulator coupled to the first input tap; a first output tap coupled to the first optical modulator so that the first optical modulator is positioned between the first input tap and the first output tap; and a controller indirectly coupled to the first input tap and the first output tap.

Abstract: Methods, apparatus, and systems are provided including an electro-absorption modulator (EAM) with local temperature control for optical communication. One aspect provides an optical EAM including a semiconductor portion configured to modulate light for transmission or reception of an optical signal. The modulator includes a temperature sensing element configured to sense temperature and to provide an output signal based on the sensed temperature, and a temperature control element configured to control temperature of the semiconductor portion based on the output signal from the temperature sensing element. In one example, the semiconductor portion includes germanium silicon (GeSi).

Abstract: A Dual Parallel (DP)-Inphase/Quadrature (I/Q) Mach-Zehnder Modulator (MZM) bias controller configured to generate a pair of orthogonal dither signals; multiply the pair of dither signals to create a second order orthogonal dither signal; and lock an Inphase (I) I MZM of a DP-I/Q MZM to a value of a corresponding I component of a transmission signal by applying the pair of orthogonal dither signal to a Quadrature (Q) MZM and a Phase (P) MZM of the DP-I/Q MZM; applying an I bias signal to the I MZM of the DP-I/Q MZM; detecting an output of the DP-I/Q MZM; and determining an I error signal in the output of the I MZM of the DP-I/Q MZM based on the product of second order dither signal and the output of the DP-I/Q MZM.

Abstract: Methods, apparatus, and systems are provided including an electro-absorption modulator (EAM) with local temperature control for optical communication. One aspect provides an optical EAM including a semiconductor portion configured to modulate light for transmission or reception of an optical signal. The modulator includes a temperature sensing element configured to sense temperature and to provide an output signal based on the sensed temperature, and a temperature control element configured to control temperature of the semiconductor portion based on the output signal from the temperature sensing element. In one example, the semiconductor portion includes germanium silicon (GeSi).

Abstract: A Dual Parallel (DP)-Inphase/Quadrature (I/Q) Mach-Zehnder Modulator (MZM) bias controller configured to generate a pair of orthogonal dither signals; multiply the pair of dither signals to create a second order orthogonal dither signal; and lock an Inphase (I) I MZM of a DP-I/Q MZM to a value of a corresponding I component of a transmission signal by applying the pair of orthogonal dither signal to a Quadrature (Q) MZM and a Phase (P) MZM of the DP-I/Q MZM; applying an I bias signal to the I MZM of the DP-I/Q MZM; detecting an output of the DP-I/Q MZM; and determining an I error signal in the output of the I MZM of the DP-I/Q MZM based on the product of second order dither signal and the output of the DP-I/Q MZM.

Abstract: An optical modulator comprises a silicon substrate, a buried oxide (BOX) layer disposed on top of the silicon substrate, and a ridge waveguide disposed on top of the BOX layer and comprising a first n-type silicon (n-Si) slab, a first gate oxide layer coupled to the first n-Si slab, a first p-type silicon (p-Si) slab coupled to the first gate oxide layer, and a light propagation path that travels sequentially through the first n-Si slab, the first gate oxide layer, and the first p-Si slab.

Abstract: An apparatus comprises: a first input tap; a first optical modulator coupled to the first input tap; a first output tap coupled to the first optical modulator so that the first optical modulator is positioned between the first input tap and the first output tap; and a controller indirectly coupled to the first input tap and the first output tap.

Abstract: An optical modulator comprises a silicon substrate, a buried oxide (BOX) layer disposed on top of the silicon substrate, and a ridge waveguide disposed on top of the BOX layer and comprising a first n-type silicon (n-Si) slab, a first gate oxide layer coupled to the first n-Si slab, a first p-type silicon (p-Si) slab coupled to the first gate oxide layer, and a light propagation path that travels sequentially through the first n-Si slab, the first gate oxide layer, and the first p-Si slab.

Abstract: An optical transceiver comprising an optical signal input, a first modulation section coupled to the optical signal input, a second modulation segment coupled to the optical signal input and positioned in serial with the first modulation section, wherein the first modulation section comprises a first digital electrical signal input, a first digital driver coupled to the first digital electrical signal input, and a first modulator coupled to the first digital driver, and wherein the second modulation section comprises a second digital electrical signal input, a second digital driver coupled to the second digital electrical signal input, and a second modulator coupled to the second digital driver, and an optical signal output coupled to the first modulation section and the second modulation section.

Abstract: An apparatus comprising a laser comprising an active layer and configured to emit an optical signal, wherein a temperature change of the laser causes the optical signal to shift in wavelength, and a heater thermally coupled to the active layer and configured to reduce a wavelength shift of the optical signal by applying heat to the active layer.

Abstract: An apparatus comprising a burst-mode laser comprising an active layer and configured to emit an optical signal during a burst period, wherein a temperature change of the burst-mode laser causes the optical signal to shift in wavelength, and a heater thermally coupled to the active layer and configured to reduce a wavelength shift of the optical signal during the burst period by applying heat to the active layer based on timing of the burst period.

Abstract: An optical transceiver comprising an optical signal input, a first modulation section coupled to the optical signal input, a second modulation section coupled to the optical signal input and positioned in serial with the first modulation section, wherein the first modulation section comprises a first digital electrical signal input, a first digital driver coupled to the first digital electrical signal input, and a first modulator coupled to the first digital driver, and wherein the second modulation section comprises a second digital electrical signal input, a second digital driver coupled to the second digital electrical signal input, and a second modulator coupled to the second digital driver, and an optical signal output coupled to the first modulation section and the second modulation section.